This invention relates to folded sheet material, regardless of whether it is in a folded or unfolded condition.
It is known from my earlier U.S. patent application Ser. No. 213,582 filed on Jun. 23, 1988 abandoned, which was filed as application Ser. No. 213,582, filed on Jun. 23, 1988 abandoned, and refiled as continuation application Ser. No. 721,910 filed on Jun. 20, 1991, now U.S. Pat. No. 5,156,898, PCT Patent Application WO 87/04284 to provide a sheet of material (hereby defined as the "sheet material" defined in my said earlier specification, which definition is hereby intended by the expression "as hereinbefore defined") having a first set of concertina folds (which term means that the folds are alternately towards and away from the front of the sheet) and, so as to be transverse to these when the sheet is folded with these folds, a second set of concertina folds, the sheet being provided with two diagonally opposite stiff portions at segments thereof, which segments are at or near diagonally opposite corners of the sheet and defined by fold/s and/or edge/s thereof. This was intended for use by one stiff portion being held in the hand and the opposite stiff portion then being moved away from it to unfold the sheet with a single movement.